Complication From Use of Alcohol to Treat Epithelial Ingrowth After Laser-Assisted In Situ Keratomileusis

Epithelial ingrowth occurs in up to 4.3% of patients following laser-assisted in situ keratomileusis.¹ Treatment varies from observation to lifting the flap and scraping away the epithelium. With recurrence, additional treatment options include the use of an excimer laser, cocaine, proparacaine hydrochloride, or alcohol on the stromal bed and flap and suturing the abnormal flap edge. Studies on the efficacy of these interventions are lacking. We report a case of total flap melting following alcohol application to the interface to treat recurrent epithelial ingrowth.

A 52-year-old woman underwent bilateral laser-assisted in situ keratomileusis for moderate myopic astigmatism. Postoperatively the patient had irritation and focal flap edema in her left eye that persisted for 6 months before epithelial ingrowth was noted. The patient's flap was lifted, scraped, and irrigated 8 months postoperatively. Twelve days later, recurrent epithelial ingrowth was observed. The retreatment consisted of elevating the flap, scraping the stromal bed and flap undersurface, applying absolute alcohol on a 6-mm sponge to the stromal bed and flap undersurface twice for 10 seconds, and irrigating the interface.

At the time of referral 6 days later, the patient's visual acuity was 20/200 with pinhole approximation, and she had a large central epithelial defect. The edematous flap made the interface difficult to examine. Her epithelial defect improved during the next week with conservative treatment, and her visual activity improved to 20/80 with pinhole approximation. Four days later, the patient returned with 80% melting of the flap (Figure 1). The remaining nasal and temporal pieces of the flap were removed and sent to the pathology department (Figure 2).

Many theories exist regarding the source of the epithelial cells in epithelial ingrowth, but most researchers believe that the cells grow under the flap from the keratotomyincision. The factors that stimulate or allow this growth are not known, but poor adhesion of the flap may be an important factor. When treating epithelial ingrowth, complete removal or death of all of the cells is important to prevent recurrence. When initial scraping and irrigating fails, additional measures such as the use of an excimer laser or alcohol on the stromal bed and flap have been attempted. Alcohol has been used in photorefractive keratectomy for many years to remove the epithelium.² However, some reports show that alcohol can induce keratocyte death and increase inflammation compared with mechanical debridement.³

Use of alcohol in this case may have influenced flap adhesion in several ways, allowing aggressive epithelial ingrowth to occur with subsequent flap melting. First, the alcohol may have caused keratocyte death on both the flap and stroma, which can affect the interaction and wound healing of these 2 surfaces. Second, the alcohol may have inadvertently touched the surface epithelium, leading to the epithelial defect, flap edema, and poor flap adhesion. Because there is a lack of basic and clinical research evaluating alcohol in the treatment of epithelial ingrowth, use of this toxic agent in the lamellar interface should be approached with caution.

Corresponding author: Carol L. Karp, MD, Bascom Palmer Eye Institute, 900 NW 17th St, Miami, FL 33136.